I'm a little confused by the Sulfate level of Burton-on-trent water profile. From what I've read, the average sulfate ppm is 600+. According to the experts, high sulfate levels can create an unpleasant bitterness in finished beer. Quoting John Palmer (RE SULFATE CONCENTRATIONS IN WATER) from How to Brew: "At concentrations over 400 ppm however, the resulting bitterness can become astringent and unpleasant, and at concentrations over 750 ppm, it can cause diarrhea."
How can water with such a high level of sulfate be used to create a quality beer?